The placing of catheters, biopsies (tissue removal) and TIPS (transingular intrahepatic portosystemic shunt, liver biopsy) form part of interventional medical operations. In these operations, 3-dimensional information of the most varied type is used, such information for instance being obtained on the basis of magnetic resonance imaging (MR), x-ray computed tomography (CT), 3D x-ray rotation angiography or by means of 3D ultrasound.
This 3-dimensional image information is used particularly with prior planning of interventional operations. The 3-dimensional image data serves here to provide information about the anatomy of the patient, for instance in order to clearly determine the location of a tumor in the body. With the actual implementation of the interventional operation, the 3-dimensional image information has until now been rarely used. A 2-dimensional imaging is generally carried out here with the aid of x-ray machines or electromagnetic classification systems (for instance the Biosense-Carto XP type).
It is also possible to display the 3-dimensional image data whilst carrying out the interventional operation. One possibility for this is the use of MPR layers (MPR stands for multiplanar reconstruction). In this way, the user selects, in a 3-dimensional image data set, the thickness and position of the layer to be displayed. The target region itself would be exclusively visible in such an image, i.e. the area of the anatomy of the patient body into which the instrument is to be introduced. In contrast, the instrument can be seen in the 2-dimensional x-ray images. A fused image is thus generated in the prior art, in which the instrument is shown at the same time, as well as the target region into which the instrument is to be introduced. The manual selection of the layer by the user renders the visualization of the 3-dimensional image data laborious, with simple tracking already not being possible, and the visualization must be continuously adjusted whilst the instrument is being guided. This involves a considerable expenditure of time during the interventional operation.
In the prior art, positioning systems are also used, for instance electrical positioning systems such as the Biosense Carto XP or positioning systems based on x-ray technology. These positioning systems however mainly provide the coordinates of the tips of the instrument, with the manner in which the information is displayed being selected by hand.